regext J. Latour
Internet-Draft CIRA
Intended status: Standards Track O. Gudmundsson
Expires: January 8, 2017 Cloudflare, Inc.
P. Wouters
Red Hat
M. Pounsett
Rightside Group, Ltd.
July 7, 2016
Third Party DNS operator to Registrars/Registries Protocol
draft-ietf-regext-dnsoperator-to-rrr-protocol-01.txt
Abstract
There are several problems that arise in the standard
Registrant/Registrar/Registry model when the operator of a zone is
neither the Registrant nor the Registrar for the delegation.
Historically the issues have been minor, and limited to difficulty
guiding the Registrant through the initial changes to the NS records
for the delegation. As this is usually a one time activity when the
operator first takes charge of the zone it has not been treated as a
serious issue.
When the domain on the other hand uses DNSSEC it necessary to make
regular (sometimes annual) changes to the delegation, in order to
track KSK rollover, by updating the delegation's DS record(s). Under
the current model this is prone to delays and errors. Even when the
Registrant has outsourced the operation of DNS to a third party the
registrant still has to be in the loop to update the DS record.
There is a need for a simple protocol that allows a third party DNS
operator to update DS and NS records in a trusted manner for a
delegation without involving the registrant for each operation. This
same protocol can be used by Registrants.
The protocol described in this draft is REST based, and when used
through an authenticated channel can be used to establish the DNSSEC
Initial Trust (to turn on DNSSEC or bootstrap DNSSEC). Once DNSSEC
trust is established this channel can be used to trigger maintenance
of delegation records such as DS, NS, and glue records. The protocol
is kept as simple as possible.
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Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 8, 2017.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notional Conventions . . . . . . . . . . . . . . . . . . . . 4
2.1. Definitions . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. RFC2119 Keywords . . . . . . . . . . . . . . . . . . . . 4
3. What is the goal? . . . . . . . . . . . . . . . . . . . . . . 4
3.1. Why DNSSEC? . . . . . . . . . . . . . . . . . . . . . . . 4
3.2. How does a child signal its parent it wants DNSSEC Trust
Anchor? . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.3. What checks are needed by parent? . . . . . . . . . . . . 5
4. Third Party DNS operator to Registrars/Registries RESTful API 6
4.1. Authentication . . . . . . . . . . . . . . . . . . . . . 6
4.2. Authorization . . . . . . . . . . . . . . . . . . . . . . 6
4.3. Base URL Locator . . . . . . . . . . . . . . . . . . . . 6
4.4. CDS resource . . . . . . . . . . . . . . . . . . . . . . 6
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4.4.1. Initial Trust Establishment (Enable DNSSEC
validation) . . . . . . . . . . . . . . . . . . . . . 6
4.4.2. Removing a DS (turn off DNSSEC) . . . . . . . . . . . 7
4.4.3. DS Maintenance (Key roll over) . . . . . . . . . . . 8
4.5. Tokens resource . . . . . . . . . . . . . . . . . . . . . 8
4.5.1. Setup Initial Trust Establishment with Challenge . . 8
4.6. Customized Error Messages . . . . . . . . . . . . . . . . 9
4.7. How to react to 403 on POST cds . . . . . . . . . . . . . 9
5. Security considerations . . . . . . . . . . . . . . . . . . . 9
6. IANA Actions . . . . . . . . . . . . . . . . . . . . . . . . 9
7. Internationalization Considerations . . . . . . . . . . . . . 10
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.1. Normative References . . . . . . . . . . . . . . . . . . 10
8.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Document History . . . . . . . . . . . . . . . . . . 11
A.1. Regex versio 01 . . . . . . . . . . . . . . . . . . . . . 11
A.2. Regex version 00 . . . . . . . . . . . . . . . . . . . . 11
A.3. Version 03 . . . . . . . . . . . . . . . . . . . . . . . 11
A.4. Version 02 . . . . . . . . . . . . . . . . . . . . . . . 11
A.5. Version 01 . . . . . . . . . . . . . . . . . . . . . . . 11
A.6. Version 00 . . . . . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
Why is this needed? DNS registration systems today are designed
around making registrations easy and fast. After the domain has been
registered there are really three options on who maintains the DNS
zone that is loaded on the "primary" DNS servers for the domain this
can be the Registrant, Registrar, or a third party DNS Operator.
Unfortunately the ease to make changes differs for each one of these
options. The Registrant needs to use the interface that the
registrar provides to update NS and DS records. The Registrar on the
other hand can make changes directly into the registration system.
The third party DNS Operator on the hand needs to go through the
Registrant to update any delegation information.
Current system does not work well, there are many types of failures
have been reported and they have been at all levels in the
registration model.
The failures result either inability to use DNSSEC or in validation
failures that case the domain to become invalid and all users that
are behind validating resolvers will not be able to to access the
domain.
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The goal of this document is to create an automated interface that
will reduce the friction in maintaining DNSSEC delegations.
2. Notional Conventions
2.1. Definitions
For the purposes of this draft, a third-party DNS Operator is any DNS
Operator responsible for a zone where the operator is neither the
Registrant nor the Registrar of record for the delegation.
Uses of the word 'Registrar' in this document may also be applied to
resellers: an entity that sells delegations through a registrar with
whom the entity has a reseller agreement.
2.2. RFC2119 Keywords
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. What is the goal?
The primary goal is to have a protocol to establish a secure chain of
trust that involves parties that are not in the traditional RRR EPP
model, or when EPP is not used.
In the general case there should be a way to find the right
Registrar/Registry entity to talk to, but it does not exist. Whois[]
is the natural protocol to carry such information but that protocol
but is unreliable and hard to parse. Its proposed successor RDAP
[RFC7480] has yet be deployed on most TLD's.
The preferred communication mechanism is to use is to use a REST
[RFC6690] call to start processing of the requested delegation
information.
3.1. Why DNSSEC?
DNSSEC [RFC4035] provides data authentication for DNS answers, having
DNSSEC enabled makes it possible to trust the answers. The biggest
obstacle in DNSSEC adoption is the initial configuration of the
DNSSEC domain trust anchor at the parent, the DS record.
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3.2. How does a child signal its parent it wants DNSSEC Trust Anchor?
The child needs first to sign the domain, then the child can "upload"
the DS record to its parent. The "normal" way to upload is to go
through registration interface, but that fails frequently. The DNS
Operator may not have access to the interface thus the registrant
needs to relay the information. For large operations this does not
scale, as evident in lack of Trust Anchors for signed deployments
that are operated by third parties.
The child can signal its desire to have DNSSEC validation enabled by
publishing one of the special DNS records CDS and/or CDNSKEY[RFC7344]
and its proposed extension [I-D.ietf-dnsop-maintain-ds].
Once the "parent" "sees" these records it SHOULD start acceptance
processing. This document covers how to make the CDS records visible
to the right parental agent.
This document and [I-D.ogud-dnsop-maintain-ds] argue that the
publication of CDS/CDNSKEY record is sufficient for the parent to
start the acceptance processing. The main point is to provide
authentication thus if the child is in "good" state then the DS
upload should be simple to accept and publish. If there is any
problem the parent does not add the DS.
In the event this protocols and its associated authentication
mechanism does not address the Registrant's security requirements to
create a secure Trust Anchor delegation then the Registrant always
has recourse by submitting its DS record via its Registrar interface
with EPP submission to the Registry.
3.3. What checks are needed by parent?
The parent upon receiving a signal that it check the child for desire
for DS record publication. The basic tests include,
1. Is the zone is signed
2. The zone has a CDS signed by a KSK referenced in the current DS,
referring to a at least one key in the current DNSKEY RRset
3. All the name-servers for the zone agree on the CDS RRset contents
Parents can perform additional tests, defined delays, queries over
TCP, ensure zone delegation best practice as per
[I-D.wallstrom-dnsop-dns-delegation-requirements] and even ask the
DNS Operator to prove they can add data to the zone, or provide a
code that is tied to the affected zone. The protocol is partially-
synchronous, i.e. the server can elect to hold connection open until
the operation has concluded or it can return that it received the
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request. It is up to the child to monitor the parent for completion
of the operation and issue possible follow-up calls.
4. Third Party DNS operator to Registrars/Registries RESTful API
The specification of this API is minimalist, but a realistic one.
Registry Lock mechanisms that prevents domain hijacking block domains
prevent certain attributes in the registry to be changed. This API
may be denied access to change the DS records for domains that are
Registry Locked (HTTP Status code 401).
4.1. Authentication
The API does not impose any unique server authentication
requirements. The server authentication provided by TLS fully
addresses the needs. In general, the API SHOULD be provided over
TLS-protected transport (e.g., HTTPS) or VPN.
4.2. Authorization
Authorization is outside the scope of this document. The CDS records
present in the zone file are indications of intention to sign/unsign/
update the DS records of the domain in the parent zone. This means
the proceeding of the action is not determined by who issued the
request. Therefore, authorization is out of scope. Registries and
registrars who plan to provide this service can, however, implement
their own policy such as IP white listing, API key, etc.
4.3. Base URL Locator
The base URL for registries or registrars who want to provide this
service to DNS Operators can be made auto-discoverable as an RDAP
extension.
4.4. CDS resource
Path: /domains/{domain}/cds {domain}: is the domain name to be
operated on
4.4.1. Initial Trust Establishment (Enable DNSSEC validation)
4.4.1.1. Request
Syntax: POST /domains/{domain}/cds
A DS record based on the CDS record in the child zone file will be
inserted into the registry and the parent zone file upon the
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successful completion of such request. If there are multiple CDS
records in the CDS RRset, multiple DS records will be added.
Either the CDS/CDNSKEY or the DNSKEY can be used to create the DS
record. Note: entity expecting CDNSKEY is still expected accept the
/cds command.
4.4.1.2. Response
o HTTP Status code 201 indicates a success.
o HTTP Status code 400 indicates a failure due to validation.
o HTTP Status code 401 indicates an unauthorized resource access.
o HTTP Status code 403 indicates a failure due to an invalid
challenge token.
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
4.4.2. Removing a DS (turn off DNSSEC)
4.4.2.1. Request
Syntax: DELETE /domains/{domain}/cds
A null CDS or CDNSKEY record mean the entire DS RRset must be
removed.
4.4.2.2. Response
o HTTP Status code 200 indicates a success.
o HTTP Status code 400 indicates a failure due to validation.
o HTTP Status code 401 indicates an unauthorized resource access.
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
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4.4.3. DS Maintenance (Key roll over)
4.4.3.1. Request
Syntax: PUT /domains/{domain}/cds
Maintenance activities are performed based on the CDS available in
the child zone. DS records may be added, removed. But the entire DS
RRset must not be deleted.
4.4.3.2. Response
o HTTP Status code 200 indicates a success.
o HTTP Status code 400 indicates a failure due to validation.
o HTTP Status code 401 indicates an unauthorized resource access.
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
4.5. Tokens resource
Path: /domains/{domain}/tokens {domain}: is the domain name to be
operated on
4.5.1. Setup Initial Trust Establishment with Challenge
4.5.1.1. Request
Syntax: POST /domains/{domain}/tokens
A random token to be included as a _delegate TXT record prior
establishing the DNSSEC initial trust.
4.5.1.2. Response
o HTTP Status code 200 indicates a success. Token included in the
body of the response, as a valid TXT record
o HTTP Status code 404 indicates the domain does not exist.
o HTTP Status code 500 indicates a failure due to unforeseeable
reasons.
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4.6. Customized Error Messages
Service providers can provide a customized error message in the
response body in addition to the HTTP status code defined in the
previous section.
This can include an Identifying number/string that can be used to
track the requests.
#Using the definitions This section at the moment contains comments
from early implementers
4.7. How to react to 403 on POST cds
The basic reaction to a 403 on POST /domains/{domain}/cds is to issue
POST /domains/{domain}/tokens command to fetch the challenge to
insert into the zone.
5. Security considerations
Supplying the DS record as proof of control is not realistic since
the domain is already publicly signed and the CDS/DS is readily
available.
Open question:?? JL?: It is not recommended the protocol be used with
high profile domains such as TLDs and governments that are DNS
operators. This protocol is meant to allow third party DNS operator
to submit the initial DS in a trusted manner without involving the
registrant.
This protocol should increase the adoption of DNSSEC and get more
zones to become validated thus overall the security gain outweighs
the possible drawbacks.
TBD This will hopefully get more zones to become validated thus
overall the security gain out weights the possible drawbacks.
risk of takeover ? risk of validation errors < declines transfer
issues
6. IANA Actions
URI ??? TBD
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7. Internationalization Considerations
This protocol is designed for machine to machine communications
8. References
8.1. Normative References
[I-D.ietf-dnsop-maintain-ds]
Gudmundsson, O. and P. Wouters, "Managing DS records from
parent via CDS/CDNSKEY", draft-ietf-dnsop-maintain-ds-03
(work in progress), June 2016.
[I-D.wallstrom-dnsop-dns-delegation-requirements]
Wallstrom, P. and J. Schlyter, "DNS Delegation
Requirements", draft-wallstrom-dnsop-dns-delegation-
requirements-00 (work in progress), February 2016.
[RFC4035] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "Protocol Modifications for the DNS Security
Extensions", RFC 4035, DOI 10.17487/RFC4035, March 2005,
<http://www.rfc-editor.org/info/rfc4035>.
[RFC7344] Kumari, W., Gudmundsson, O., and G. Barwood, "Automating
DNSSEC Delegation Trust Maintenance", RFC 7344, DOI
10.17487/RFC7344, September 2014,
<http://www.rfc-editor.org/info/rfc7344>.
8.2. Informative References
[I-D.ogud-dnsop-maintain-ds]
Gu[eth]mundsson, O. and P. Wouters, "Managing DS records
from parent via CDS/CDNSKEY", draft-ogud-dnsop-maintain-
ds-00 (work in progress), October 2015.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC6690] Shelby, Z., "Constrained RESTful Environments (CoRE) Link
Format", RFC 6690, DOI 10.17487/RFC6690, August 2012,
<http://www.rfc-editor.org/info/rfc6690>.
[RFC7480] Newton, A., Ellacott, B., and N. Kong, "HTTP Usage in the
Registration Data Access Protocol (RDAP)", RFC 7480, DOI
10.17487/RFC7480, March 2015,
<http://www.rfc-editor.org/info/rfc7480>.
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Appendix A. Document History
A.1. Regex versio 01
Rewrote Abstract and Into (MP) Introduced code 401 when changes are
not allowed Text edits and clarifications.
A.2. Regex version 00
Working group document same as 03, just track changed to standard
A.3. Version 03
Clarified based on comments and questions from early implementors
A.4. Version 02
Reflected comments on mailing lists
A.5. Version 01
This version adds a full REST definition this is based on suggestions
from Jakob Schlyter.
A.6. Version 00
First rough version
Authors' Addresses
Jacques Latour
CIRA
Email: jacques.latour@cira.ca
Olafur Gudmundsson
Cloudflare, Inc.
Email: olafur+ietf@cloudflare.com
Paul Wouters
Red Hat
Email: paul@nohats.ca
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Matthew Pounsett
Rightside Group, Ltd.
Email: matt@conundrum.com
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